1. Field of the Invention
The present invention relates to computing devices and, more particularly, to recognition of user input by constrained computing devices.
2. Description of the Related Art
Today, various types of wireless communication devices are available. Examples of wireless communication devices include pagers, mobile phones, Personal Digital Assistants (PDAs), palm-top computers, and electronic schedulers. In using wireless communication devices, there is often a need to enter text information. Conventionally, wireless communication devices have a keyboard or keypad that allow users of the wireless communication devices to enter text information. Unfortunately, given the reduced size of wireless communication devices, the size of their keyboards or keypads are limited (or constrained).
Many wireless communication devices, such as mobile phones, use a standard 12 key telephone-type keypad for entering numeric or text data. However, with only 12 keys, many of the keys have to represent multiple characters. As a result, each key press is ambiguous as to the character to be entered. For example, in one case, entering the “8” key, ambiguously refers to one of “8”, “T”, “U” or “V”. Various conventional techniques have been used to disambiguate the character being entered through multiple key presses. As an example, after the initial key press, the user is presented with a list of choices on a display screen and then the desired character is selected from the displayed list using additional key presses. The list of choices can be order based on their likelihood of appropriateness given the previous character. Nevertheless, this approach not only requires multiple key presses but also requires the user to focus attention onto a display screen. As another example, after the initial key presses for the characters of a word have been entered, a built-in dictionary can be consulted to disambiguate the word the user is attempting to enter. This approach requires the user to know the correct spelling for the word and requires the dictionary to support the desired word. This approach is also unreliable for short words.
Thus, there is a need for improved techniques to disambiguate key entries for constrained keyboards.